<?php
$s='i am a teacher.';
echo $s,"\n";
$a="he say:\"i'm a student.\"";
echo $a,"\n";
$b='计算机1234';
printf("[%d][%5d][%05d][%X][%5X]{%05X]\n",26,26,26,26,26,26);
echo strlen($b),"\n";
echo ord('0'),"\n";
echo ord('0123'),"\n";
echo substr($b,3),"\n";
echo substr($b,6,4),"\n";
for($i=0,$l=strlen($b);$i<$l;++$i){
    printf("%02X", ord(substr($a,$i)));
}
echo "\n";
echo ord(substr($a,0)),"\n";
$d="\xE8\xA1\u{7B97}\u{673A}";
echo $d,"\n";